Mozilla has effectively postponed Firefox's controversial third-party cookie-blocking policy for several months.

Yesterday, the open-source developer announced it was collaborating with a new initiative, dubbed "Cookie Clearinghouse," or CCH, launched by Stanford University's Center for Internet and Society.

"Today Mozilla is committing to work ... to develop the CCH so that browsers can use its lists to manage exceptions to a visited-based third-party cookie block," wrote Brendan Eich, Mozilla's CTO, in a post on his personal blog.

The CCH, which is headed by Alexia McDonald, director of Stanford's Center for Internet and Society -- and formerly a part-time privacy research officer at Mozilla -- will come up with a list of sites to be blocked by browsers, as well as another that includes blocking exceptions.

Those lists would be analogous to the blacklists and whitelists used for other purposes, like those that prevent browser users from visiting potentially-malicious websites.

Such centralized, constantly-updated lists, said Eich, are necessary to solve the false positive and false negative results that have plagued Firefox's third-party cookie blocker.

Cookies are used by online advertisers to track users' Web movements, then deliver targeted ads. Firefox was to allow cookies presented from domains users actually visit -- dubbed a "first-party" site -- but block those generated by a third-party domain unless the user had previously visited the cookie's site-of-origin.

Computerworld